1. Field of the Invention
The present invention relates to a fabrication method of a color-changeable element, particularly to a fabrication method of an electrochromic element.
2. Description of the Related Art
Generally, a conventional electrochromic unit has a laminated structure, and at least one transparent electrode layer is layered on a side surface of the laminated structure. The conventional electrochromic unit generally further includes a couple of glass substrates. If the electrochromic unit is applied to a car-used rearview mirror, one of the glass substrates is able to reflex light. A transparent conductive layer is layered on one side surface of the glass substrates. For example, indium tin oxide (ITO) layer is coating on the side surface. The glass substrates oppositely face to each other and the electrochromic layer is attached therebetween, to form an electrochromic unit. The electrochromic unit is electrically connected to a power source via the ITO layer.
When various driving voltages are respectively applied to the above conventional electrochromic unit, the color of the electrochromic unit will change according to one the corresponding driving voltage. However, the conventional electrochromic unit requires a higher driving voltage, performs with fewer color-levels and worse color contrast. Additionally, after a driving voltage is applied to the electrochromic device and then cut off, the color of the electrochromic device can just maintain for few hours (short-time memory effect). Besides, the electrochromic unit is generally applied to LCD, and thus requiring a higher driving voltage and being unable to maintain the appearance color. Furthermore, the transmittance of the electrochromic device for infrared is considerably high, thus infrared and harmful light cannot be sufficiently isolated.